I'm really cheap so using an ether anywhere other than boss battles is like a sin! They're so expensive. But, since I'm such a magic-god, I'm stuck with 2 or 3 mages for the whole game who do nothing but physical attack outside of boss battles and slight healing. This slows things down a bit, but meh, I love 'em. (Yes, Magic Waltz is a must)

If there were no MP, magic would probably be lowered next to worthless and if not so, then the game would just be way too easy.